Riding lawn mower



FIG. 1 is a top view of the riding lawn mower;

FIG. 2 is a view showing one side thereof;

FIG. 3 is a view showing the opposite side thereof;

FIG. 4 is a view showing the front thereof; and

FIG. 5 is a view showing the rear thereof. 

The ornamental design for a riding lawn mower, as shown. 